Calculadoras en línea gratis
1RM estimada a partir de peso y repeticiones (Epley & Brzycki)
Whether you're a seasoned powerlifter or just getting serious about strength training, knowing your one rep max (1RM) is essential. Our free 1RM Calculator helps you estimate the maximum weight you can lift for a single repetition — without the risk of actually maxing out every session.
Your one rep max is the heaviest weight you can lift for exactly one complete repetition with proper form. It's the gold standard for measuring raw strength in exercises like the squat, bench press, deadlift, and overhead press. Coaches and athletes use 1RM values to structure training programs, set progressive overload targets, and track long-term progress.
Testing your true 1RM in the gym carries injury risk, especially without a spotter or when you're fatigued. That's why using a 1RM calculator based on submaximal lifts is a safer and highly practical alternative.
Our calculator uses well-established strength estimation formulas to predict your one rep max from a weight you've already lifted for multiple reps. Simply enter:
The calculator then applies proven formulas — including the Epley, Brzycki, Lander, and O'Conner methods — and returns an estimated 1RM along with percentage-based training weights so you can plan your workouts with precision.
One of the most widely used equations in strength sports: 1RM = Weight × (1 + Reps / 30). It works best for moderate rep ranges (around 3–10 reps) and slightly overestimates for very high rep sets.
A favorite among powerlifters: 1RM = Weight × (36 / (37 – Reps)). This formula is considered very accurate for rep ranges between 2 and 10 and tends to be more conservative than Epley.
Developed with a focus on accuracy across a wider rep range: 1RM = (100 × Weight) / (101.3 – 2.67123 × Reps). It's a solid middle-ground option for most lifters.
Simple and beginner-friendly: 1RM = Weight × (1 + 0.025 × Reps). It tends to produce slightly lower estimates, making it a conservative choice for newer athletes.
Once you know your 1RM, you can structure every workout around training percentages. This method, used by elite coaches worldwide, ensures you're training at the right intensity for your goals:
Our calculator automatically displays these percentage breakdowns so you can jump straight into planning without doing the math yourself.
This tool is valuable for anyone involved in resistance training, including:
For the best results with your 1RM calculation, keep these tips in mind:
1RM calculators provide a reliable estimate rather than a guaranteed exact number. Accuracy depends on your rep range, fatigue levels, and individual physiology. Most formulas are within 5–10% of your true max when used correctly with moderate rep ranges.
Research consistently shows that 3 to 6 repetitions yield the most accurate 1RM predictions. As rep count increases beyond 10, accuracy decreases because fatigue becomes a bigger factor than pure strength.
Yes — the 1RM formula applies to any barbell or dumbbell exercise, including squats, bench presses, deadlifts, rows, and overhead presses. Keep in mind that isolation exercises like curls tend to have more variability, so results may be less precise.
If you're following a consistent training program, recalculating every 4 to 8 weeks is a good practice. This aligns with typical mesocycle lengths and gives your strength enough time to meaningfully progress between measurements.
Testing your actual 1RM can be motivating and gives you a definitive number, but it should only be done when you're well-rested, properly warmed up, and have an experienced spotter. For most recreational lifters, calculator estimates are more than sufficient for programming purposes.